Device for faciltating the aiming of an antenna enabling signals transmitted by one or several satelites to be picked up

ABSTRACT

The invention relates to a device for facilitating the aiming of an antenna enabling signals transmitted by one or several satellites to be picked up, this device includes a compass, the body of which ( 3 ) is provided with an attachment system ( 5 ) on the antenna. According to the invention, the compass includes a dial onto which the magnetic south and the name of the satellites in their geographical position are transferred and in that the body ( 3 ) includes a mark ( 4 ) for aiming the antenna by simply rotating it in azimuth.

The present invention relates to a device which facilitates the aimingof an antenna or receiver in the general sense, such as a parabolicantenna enabling signals, for example radio and/or television signals,transmitted by one or several satellites to be picked up.

Aiming an antenna at one or several satellites is a difficult operation.Indeed, the elevation of the antenna (up/down adjustment) needs to beadjusted, and then the azimuth (left/right adjustment) with a highprecision, in order to receive the signals transmitted by the aimedsatellite(s) and thereby to be able to obtain images or soundsbroadcasted by this (these) satellite(s).

All the television and/or radio programme broadcasting satellites arepositioned eastwards or westwards from the geographical south. In orderto aim an antenna at a satellite, this antenna already needs to bedirected towards the south and then orientated to the left (if the aimedsatellite is positioned eastwards) or to the right (if the aimedsatellite is positioned westwards).

There are two kinds of radio/television signals transmitted bysatellites: analog signals and digital signals.

In order to pick up analog signals, the antenna is connected to ananalog demodulator itself connected to a TV set. In this case, uponaiming the antenna, it is sufficient, after having directed the lattertowards the south, to rotate it slowly to the left or right. When theantenna picks up a signal transmitted by a satellite, an image willappear on the screen of the TV set, of course, provided that thedemodulator is adjusted on a suitable channel and that the elevation ofthe antenna is correct, otherwise the antenna will never pick up anysignal.

To pick up digital signals, the antenna is connected to a digitaldemodulator, itself connected to a TV set. Unlike the analogdemodulator, by directing the antenna towards the south and rotating itslowly from left to right, it will not be possible to know whether thelatter picks up a signal or not because for digital signals, a long timeis required after receiving a signal for demodulating the latter(transformed into an image on the TV set). This time is variableaccording to the digital demodulator used. Moreover, the aimingprecision for digital signals should be very high of the order of a fewdegrees. Consequently, many people never manage to aim their antennawith a digital demodulator and tend to bring back the equipment to theirreseller, generating significant and unjustified returns to theafter-sales service, endured by companies distributing this kind ofproducts today.

To facilitate the aiming of an antenna at a satellite, the state of theart has suggested different solutions based on the use of a compassindicating magnetic south. Thus, for example, U.S. Pat. No. 5,274,926describes an instrument for assisting the aiming of antennas, includinga sphere to which a map is transferred, illustrating an area of thesurface of the Earth, served by the satellite. This sphere is mountedonto a support equipped with a line of sight for the satellite and witha compass associated with a spirit level. To aim the line of sight ofthe instrument at the satellite, the sphere is displaced so as tosuperimpose a point of the compass with a point of the map illustratingthe location where the instrument is used. It is clear that such aninstrument can only have a very limited precision as the location wherethe instrument is used, is illustrated on a sphere which may only have areduced size in practice.

Document DE 295 18 105 also describes a device for adjusting satelliteantennas including a compass placed at the center of a disc on whichposition lines are illustrated for cities corresponding to thegeographical application area of the satellite antenna. The discincludes a mark to be aligned with an arrow for locating the satellite,placed on the support of the antenna. The support of the antenna ispivoted so that the needle of the compass coincides with the positionline bearing the name of the city where the antenna is used. It is clearthat such a device is not universal because it requires the making of agreat number of discs corresponding to different geographic areas.

Document JP 60 206 302 describes an aiming instrument for an antennawith the help of a spherical level with a hemispherical bodyillustrating a map and provided at its base with a passage window forthe needle of a compass. Such an instrument also has a limited precisionas the set-up site appears on a body with a very reduced size.

Document U.S. 2002/005,816 also relates to a device for alignment ofsatellite antennas, including a tubular fitting component on the supportarm of the antenna. This tubular component is provided with a spiritlevel, a compass and a map able to show the angle along which thesupport for attaching the antenna is positioned on the arm in order toalign the antenna. In addition to the fact that such a device requireslocalization of the compass at the focal point of the antenna, whichdisrupts its operation, such a device also has poor aiming precision bythe positioning of a compass near a map.

The object of the invention is therefore directed to finding a remedy tothe drawbacks of the prior art by providing a device for facilitatingthe aiming of an antenna, having good precision and quasi-universal useregardless of the set-up location of the antenna.

Another object of the invention is to provide a device for facilitatingthe aiming of an antenna, with a simple design and reduced costs.

To achieve such goals, the object of the invention relates to a devicefor facilitating the aiming of an antenna enabling signals transmittedby one or several satellites to be picked up, this device including acompass, the body of which is provided with an attachment system on theantenna.

According to the invention, the compass includes a dial onto whichmagnetic south and the name of the satellites at their geographicalpositions are transferred and the body includes a mark for aiming theantenna by having it simply rotate in azimuth.

The device according to the invention implements a (analog or digital)compass provided with an attachment system either by bonding and/orattaching with clips and/or snapping on and/or screwing and/or rivetingand/or any other means making the device integral with the antenna.

For more ease, the device according to the invention is also called apointer. The pointer may be attached in any location on an antenna, butit will preferably be attached onto the LNB, i.e. on the electronic headof the antenna or on the attachment bracket of the LNB.

Various other features will become apparent from the description madebelow with reference to the appended drawings which show embodiments ofthe object of the invention, as non-limiting examples.

FIG. 1 is a perspective view of an alternative embodiment of the pointeraccording to the invention using a compass.

FIG. 2 illustrates a parabolic antenna, the electronic head of which isequipped with a pointer according to the invention.

FIG. 3 is a top view of a pointer according to the invention using acompass.

FIG. 4 is a profile view of a pointer according to the invention using acompass.

As apparent in the figures, the device or the pointer 7 illustrated asusing a compass, has a dome 1 including a dial for the compass and ontowhich the names of several, i.e., in the illustrated example six,radio/television program broadcasting satellites are printed ortransferred. These names have been printed on either side of themagnetic south (represented with an S on FIG. 1 and FIG. 3) in theirgeographical positions. Conventionally, the dial of the compass ismobile so as to be locked on the Earth's magnetic axis. As apparent inthe figures, the dial is visible through a dome of translucent material.The pointer thereby forms a spirit level with the presence of a liquidbetween the plastic dome and the dial which is made in a known way witha sphere, a part of which, the dome, is visible.

Preferably, the translucent material dome is provided with a mark 2, forexample a white mark, used for aiming the antenna more particularly whenapplying a calibration or an adjustment related to the geographicalset-up location. This mark 2 should be aligned (by rotating the antennato the left or to the right) with the name of the aimed satellite. InFIG. 1, the mark 2 is aligned with the south, and the antenna thereforeaims at the south. If the mark 2 is aligned with the Telecom lettering,the antenna 6 aims at the Telecom satellite.

The pointer has a body 3 from which the dome 1 rises. The body 3 has anaiming mark 4 for the antenna, for example a white mark in theillustrated example, located at the center (east/west) of the body. Thebody 3 is provided with an attachment system 5 on an antenna 6. In theillustrated example, the attachment system 5 is formed with a jointedtab on the body along an axis 8 allowing the compass to be alwayspositioned horizontally. For example, the tab 5 may include an adhesiveor self-adhesive means. Preferably, and as more specifically apparent inFIG. 2, the pointer 7 is adhered to the attachment bracket of theelectronic head 9 (LNB) of the parabolic antenna 6, by means of tab 5.

As apparent in the example illustrated in FIG. 4, without anyapplication of a geographical compensation, the mark 2 of the plasticdome is aligned with the mark 4 of the body of the pointer. Aiming theantenna at a satellite is achieved by simply rotating the antenna inazimuth so as to bring the satellite name borne by the dial in alignmentwith the mark 2 of the plastic dome, i.e., in the relevant example, withthe aiming mark 4 borne by the body 3. In the example illustrated inFIGS. 3 and 4, the adjustment is made on the Telecom satellite.

According to a preferred alternative embodiment, the plastic dome mayrotate or pivot over 360° relatively to the body 3 of the pointer, whichallows a calibration of the pointer to be performed as explained aboveaccording to the geographical position of the installer (Portugal,Greece, etc.). According to this alternative, on either side of the mark4 formed by the body 3, indicators or marks (not visible in FIG. 1) arepositioned, for example every five degrees, both eastwards andwestwards. Their role is to allow the pointer to be precisely calibratedby aligning the mark 2 with the indicator corresponding to thegeographical offset of the installer. The antenna is rotated to the leftor right so that the mark 2 becomes aligned with the name of the aimedsatellite.

In order to adjust a satellite antenna 6, it is highly recommended tostand behind the latter so as to be able to pivot it in azimuth(left/right) easily. It is for this reason that it is preferable thatthe compass of the pointer be inverted by 180° relatively to the normal,so that the installer standing behind the antenna may directly read onthe dial of the compass the aimed direction during the aiming. Withoutthis, one would have to move round the antenna in order to find out whatthe compass is showing.

According to another feature of the invention more particularlyillustrated in FIG. 3, the pointer using a compass includes a spiritlevel 10 visible through the transparent dome which is provided with amark 11, for example a white mark. This mark 11 should be aligned withthe spirit level in both axes in order to guarantee that the attachmentof the antenna is level and to facilitate the horizontal adjustment ofthe pointer.

The invention is not limited to the described and illustrated examplessince various changes may be made thereto without departing from itsscope.

1. A device for facilitating the aiming of an antenna (6) allowingsignals transmitted by one or several satellites to be picked up, thisdevice including a compass, the body (3) of which is provided with anattachment system (5) on the antenna, wherein the compass includes adial on which the magnetic south and the name of the satellites at theirgeographical position, having been transferred and in that the body (3)includes a mark (4) for aiming the antenna by simply rotating it inazimuth.
 2. The device according to claim 1, wherein the compassincludes a dial embodied by the body (3) or an annulus or ring.
 3. Thedevice according to claim 1, wherein the compass includes a dialembodied by a dome.
 4. The device according to claim 1, wherein itincludes a mark which may rotate relatively to the body (3) over a rangeof 360° in order to compensate the geographical offset of a satelliterelatively to the magnetic south according to the geographical positionof the installer.
 5. The device according to claim 3, wherein itincludes a translucent dome provided at its top with a mark (11)allowing the use of a spirit level (10) for checking the horizontalityof the compass.
 6. The device according to claim 5, wherein thetranslucent dome is provided with a mark (2) and may rotate relativelyto the body (3).
 7. The device according to claim 1, wherein the mark(4) for aiming the antenna includes on either side, eastwards andwestwards, marks, for example positioned every five degrees, in order toalign the mark (2) of the translucent dome with one of said markscorresponding to the geographical offset of the installer.
 8. The deviceaccording to claim 1, wherein it includes a jointed attachment tab (5)on the body allowing the elevation of the antenna to be compensated byproviding horizontal positioning of the dome.
 9. The device according toclaim 1, wherein the compass is inverted by 180° relatively to thenormal direction so that in the mounted position on the electronic headof the antenna, the aimed direction during the aiming may be directlyread on the dial.
 10. The device according to claim 2, wherein itincludes a mark which may rotate relatively to the body (3) over a rangeof 360° in order to compensate the geographical offset of a satelliterelatively to the magnetic south according to the geographical positionof the installer.
 11. The device according to claim 3, wherein itincludes a mark which may rotate relatively to the body (3) over a rangeof 360° in order to compensate the geographical offset of a satelliterelatively to the magnetic south according to the geographical positionof the installer.
 12. The device according to claim 6, wherein the mark(4) for aiming the antenna includes on either side, eastwards andwestwards, marks, for example positioned every five degrees, in order toalign the mark (2) of the translucent dome with one of said markscorresponding to the geographical offset of the installer.